For example, in order to provide air conditioning to a relatively large space to be air-conditioned such as a shop, a restaurant or an office in a building, an indoor unit of the type embedded in a ceiling or of the type hung from a ceiling has heretofore generally been disposed at a ceiling located above the space to be air-conditioned.
In providing air conditioning to such a large space to be air-conditioned using an indoor unit of the type embedded in a ceiling or of the type hung from a ceiling, air flows have conventionally been discharged uniformly from respective outlets of the indoor unit without giving any thoughts to air conditioning requirement such as distribution of heat load or distribution of people within the space to be air-conditioned. This has been causing, for example, a problem that temperature variations occur in the space to be air-conditioned to create an area inferior in comfort accompanied with draftiness, another problem that an area without the presence of a person is air-conditioned as with an area with the presence of a person, and still another problem that energy conservation is impaired because of the execution of unnecessary and needless air conditioning as a result of, for example, always running an air conditioning apparatus under a predetermined condition even though the heat load distribution in the space to be air-conditioned varies with time depending on criteria such as season, time of day and the number of people present in a room.
Proposed solutions to these prior-art problems include: a technique in which distribution of heat load or distribution of people in a space to be air-conditioned, for example, is detected, and based on the detected information, the characteristic of an air flow discharged through an outlet of an indoor unit, e.g., quantity of air discharge, temperature of air discharge, velocity of air discharge or direction of air discharge, is appropriately controlled, thus performing air conditioning that achieves comfort at all times and accomplishes outstanding energy conservation (see Japanese Unexamined Patent Publication No. 5-203244 and Japanese Unexamined Patent Publication No. 5-306829, for example); and another technique in which an infrared sensor is used as a means for detecting, for example, distribution of heat load (see Japanese Unexamined Patent Publication No. 5-20659, for example).
Solution
However, although the proposed prior-art techniques described above as well-known examples are theoretically thought to provide necessary functionality and make the expected effects obtainable, the technical disclosures thereof are not implementable or not realistic, and therefore, the fact is that the above-described techniques are not yet brought into practical use. Accordingly, there is a strong demand that practice of the above-described techniques be established and implemented as soon as possible. In addition, a control mode suitable for achievement of the comfort of air conditioning and energy conservation is likewise demanded.
Hence, the object of the present invention is to achieve both of comfort and energy conservation with the use of an air conditioning apparatus including: a detection means for detecting, for example, a heat load; an air flow changing means for changing the characteristic of a discharged air flow; and a control means for the air flow changing means, by providing each of these means in more implementable and realistic form to promote the practical use thereof and by providing a control mode of air conditioning suitable for improvement of comfort and energy conservation.